Bleaching and dyeing; fluid treatment and chemical modification – Cleaning or laundering – Scouring – degreasing or bowking
Reexamination Certificate
2000-04-04
2001-10-02
Gupta, Yogendra N. (Department: 1751)
Bleaching and dyeing; fluid treatment and chemical modification
Cleaning or laundering
Scouring, degreasing or bowking
C510S392000, C435S263000, C134S022140, C008S181000
Reexamination Certificate
active
06296671
ABSTRACT:
The present invention relates to a process for using polymethylgalacturonases in the textile, detergent and cellulose fiber processing industries and to a cleaning composition comprising a polymethylgalacturonase.
BACKGROUND OF THE INVENTION
Pectin polymers are important constituents of plant cell walls. Pectin is a hetero-polysaccharide with a backbone composed of alternating homogalacturonan (smooth regions) and rhamnogalacturonan (hairy regions). The smooth regions are linear polymers of 1,4-linked alpha-D-galacturonic acid. The galacturonic acid residues can be methyl-esterified on the carboxyl group to a varying degree, usually in a non-random fashion with blocks of polygalacturonic acid being completely methyl-esterified.
Pectinases can be classified according to their preferential substrate, highly methyl-esterified pectin or low methyl-esterified pectin and polygalacturonic acid (pectate), and their reaction mechanism, beta-elimination or hydrolysis. Pectinases can be mainly endo-acting, cutting the polymer at random sites within the chain to give a mixture of oligomers, or they may be exo-acting, attacking from one end of the polymer and producing monomers or dimers. Several pectinase activities acting on the smooth regions of pectin are included in the classification of enzymes provided by the Enzyme Nomenclature (1992) such as polymethylgalacturonase (EC 4.2.2.2), pectin lyase (EC 4.2.2.10), polygalacturonase (EC 3.2.1.15), exo-polygalacturonase (EC 3.2.1.67), exo-polygalacturonate lyase (EC 4.2.2.9) and exo-poly-alpha-galacturonosidase (EC 3.2.1.82).
Glycosyl hydrolases are classified into families according to their three-dimensional structure or folding; conventionally the Clustal W method is used the for family determination. Based on amino acid sequence alignment and the Clustal W method, a polypeptide or protein can be classified into a specific glycosyl hydrolase family, ie either a known family or a novel and hitherto unknown family (The Sanger Centre: Protein Families Database of alignments and HMMs; www. sanger.ac.uk). At present known polymethylgalacturonases belong to family 28 of glycosyl hydrolases (ExPASy—molecular biology WWW server of the Swiss Institute of Bioinformatics (SIB)).
Polymethylgalacturonases have been cloned from various microbial organisms. However, up till very recently all polymethylgalacturonases were known as requiring divalent cations for maximum activity, calcium ions being the most stimulatory. In contrast hereto, Japanese patent application Kokai 10-313858 discloses a novel polymethylgalacturonase of family 28 which is believed not to require the presence of divalent cations for maximum activity, ie this novel enzyme is capable of exerting its action in an aqueous solution which further comprises calcium chelators. Calcium chelators are known to be present in a number of industrial processes including scouring of cotton.
It is an object of the present invention to provide improved industrial enzymatic processes which are more efficient and/or have higher cost-benefit than the hitherto known processes.
SUMMARY OF THE INVENTION
The inventors have now found that pectin hydrolases such as polymethylgalacturonases exhibiting hydrolytic activity against protopectic acid and methylated polygalacturonic acid show excellent performance in various industrial processes, and are especially useful for the treatment of cellulosic material, especially cellulose-containing fiber, yarn, woven or non-woven fabric, treatment of mechanical paper-making pulps or recycled waste paper, and for retting of fibres. The enzymatic treatment can be carried out during the processing of cellulosic material into a material ready for garment manufacture or fabric manufacture, e.g. in the desizing or scouring step; or during industrial or household laundering of such fabric or garment.
It is contemplated that the polymethylgalacturonase enzymes described herein are very effective for use in an enzymatic scouring process in the preparation of cellulosic material e.g. for proper response in subsequent dyeing operations. Further, it is contemplated that detergent compositions comprising the polymethylgalacturonases described herein are capable of removing or bleaching certain soils or stains present on laundry, especially soils and spots resulting from pectin or highly methylated polygalacturonic acid containing food, plants, and the like. It is also contemplated that treatment with detergent compositions comprising the polymethylgalacturonase enzyme can prevent binding of certain soils to the cellulosic material. The polymethylgalacturonase enzymes are also useful as ingredients in hard surface cleaning compositions having the effect of removing or assisting in removing certain soils or stains from hard surfaces in need of cleaning.
Accordingly, the present invention relates to a process for degradation or modification of fibres, yarn or woven or non-woven fabric comprising plant material, the process comprising the step of subjecting the fibres or fabric to a treatment, in an aqueous solution, with an effective amount of a polymethylgalacturonase enzyme comprising the amino acid sequence of SEQ ID NO:1 or an amino acid sequence having at least 70% sequence identity with SEQ ID NO:1.
In a further aspect, the present invention relates to a cleaning or laundering detergent composition comprising an enzyme having substantial polymethylgalacturonase activity and a surfactant.
DEFINITIONS
The term “enzyme core” denotes the part of a single- or multi-domain structure polypeptide exhibiting enzymatic activity which part is a single domain part containing the catalytically active domain. Accordingly, the enzyme core does not contain other domains than the catalytic domain.
The term “pectin” denotes pectate, polygalacturonic acid, and pectin which may be esterified or methylated to a higher or lower degree.
The term “pectinase” denotes a pectinase enzyme defined according to the art where pectinases are a group of enzymes that cleave glycosidic linkages of pectic substances mainly poly(1,4-alpha-D-galacturonide and its derivatives(Sakai et al., Pectin, pectinase and protopectinase: production, properties and applications, pp 213-294 in: Advances in Applied Microbiology vol: 39,1993).
For purposes of the present invention, the degree of identity (percent sequence identity) between two amino acid sequences is determined by conventional methods, by means of computer programs known in the art such as GAP provided in the GCG program package (Program Manual for the Wisconsin Package, Version 9.1, Genetics Computer Group, 575 Science Drive, Madison, Wis., USA 53711) as disclosed in Needleman, S. B. and Wunsch, C. D., (1970), Journal of Molecular Biology, 48, 443-453, which is hereby incorporated by reference in its entirety. GAP is used with the following settings for polypeptide sequence comparison: GAP creation penalty of 30 and GAP extension penalty of 1.
REFERENCES:
patent: 3867553 (1975-02-01), Hitze et al.
patent: 4012 351 A1 (1991-10-01), None
patent: 0 421 919 A2 (1991-04-01), None
patent: 10313858-A (1997-05-01), None
patent: WO 95/16808 (1995-06-01), None
patent: WO 98/06809 (1998-02-01), None
Abstract of Japanese Patent JP 10313858 A, 1997.
Kristensen Henrik
Schulein Martin
Elhilo Eisa
Gargell Jason I.
Gupta Yogendra N.
Lambiris Elias J.
Novorymeo A/S
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